The short answer is... a whole heck of a lot.
The Big Question
Without a doubt, the single question that I get asked the most is "What does a home inspector look for?" - It's a great question, so I'm going to do my best to explain it.
At the most basic level, home inspectors are trying to determine if a house is "healthy".
First Impressions
If you stand back and look at it from the road, what is your gut feeling? Is the house leaning? Does it look run down and overgrown? Think of it like asking, "does this person look healthy?" This big picture impression is where it all starts.
Systems of a House
A house, much like your body, has many different systems. Each of these systems has a specific job to do.
Your respiratory system provides oxygen, your circulatory system distributes it, and your skeleton supports everything.
In a house, the roof system diverts water, the foundation supports the house, and the electrical system provides power.
Is each of these systems doing its job?
Inspecting Each System
The most important thing we ask of each system is: what job does it need to do, and is it working the way it should? Here are the basic items we look at when inspecting each of the systems.
Exterior
Wall coverings (siding), flashing, and trim
Exterior doors and windows
Decks, balconies, and porches
Walkways and driveways
Carports
Lot grading and vegetation
Roof
Roof coverings (like shingles)
Drainage system and gutters
Flashings
Skylights
Chimneys and vents
Structure
Foundation
Wall framing
Floor framing
Roof structure
Posts and beams
HVAC
Furnace and/or other heating equipment
Air conditioners
Ventilation and fans
Ducts
Plumbing
Supply and waste pipes
Fixtures and faucets
Drains and sumps
Electrical
Service drop (power coming in)
Electrical panel
Distribution wiring
Fixtures and lighting
Interior
Walls, ceilings, and floors
Stairs
Kitchens
Bathrooms
Fireplace
Woodstoves and fireplaces
Chimneys
Flues
Venting systems
A full breakdown of the HIABC Scope of Inspection is available here.
Looking For Clues
In addition to looking at the individual performance of a system, we are looking for clues to less obvious issues. A drywall crack might not mean much on its own, but combined with a door that won't close, and a sagging beam in the basement, we start to get an idea of what the underlying issues might be.
Putting it All Together
There are many hundreds of things that might be wrong with each of these systems. The goal is not to find every single small issue, but rather to determine if it is functioning properly overall. For example: the roof might be aged, but if it keeps water out, it's still working properly.
We Don't Look For Building Code
A home inspection is not a building code inspection. Building codes change constantly, and what was common and acceptable when the house was built, may not be the way it's done anymore that doesn't mean it won't do its job! To learn more about the difference between home and building code inspections, read our blog post about it here.
Key Points
We look at the big picture: does this house look healthy?
A house is made up of many systems, much like your body.
We ask of each individual system: is it doing its job?
We look for seemingly small clues that are significant when considered together.
Is everything functioning as intended overall?
We aren't looking for building code.